The Pentagon also reportedly stationed a number of U.S. military units at the Al Asad Air Base in Anbar province in the western part of the country.
The U.S. troops on the ground in Iraq are allegedly part of a 20,000-man force being positioned in the country in response to concerns from Washington over concerns of a chemical weapons attack against Syrian rebels by embattled President Bashar Assad.
But DOD spokesman Lt. Col. Wesley Miller told The Hill on Monday he was unaware of any information indicating that additional American forces have been sent to Iraq for any reason.
"Our [troop] numbers have been fairly stable at about 200 military personnel since December 2011," Miller said, noting those 200 troops have been assigned to Office of Security Cooperation-Iraq (OSC-I) since 2011.
All U.S. combat forces were withdrawn from Iraq last December. Aside from the handful of American forces at OSC-I, Washington and Baghdad could not reach an agreement on a postwar American force for the country.
That decision has resulted in a tenuous security situation in Iraq, punctuated by rampant sectarian violence that threatens to tear the nation apart, Sen. Joe Lieberman (I-Conn.) told the Hill last Tuesday.
News of the U.S. deployment also comes amid reports that DOD is beginning to piece together the details of a possible military response in Syria, should Assad decide to unleash the country's chemical weapons stockpiles against Syrian citizens.
Assad forces began shuffling around previously undisclosed stockpiles of sarin nerve agent, mustard gas and cyanide to various parts of Syria in July.
Both President Obama and Defense Secretary Leon Panetta issued stern warnings to the Assad regime shortly after U.S. intelligence showed Assad's forces outfitting air-to-ground bombs with sarin gas at two airfields in Syria.
Obama made "absolutely clear" during a Monday speech at the National Defense University in Washington that the use of chemical weapons by the Assad government against rebel fighters "would be totally unacceptable" and trigger an immediate and overwhelming response by the United States.
"The world is watching," the president said. "If you make the tragic mistake of using these weapons, there where be consequences, and you will be held accountable."
Days later, Panetta echoed the president's comments, saying if chemical weapons were used against Syrians, such an attack would cross a "red line" that would draw an armed U.S. response.
When asked Friday about DOD's planning efforts for a possible military strike against targets inside Syria, Pentagon press secretary George Little replied that the Pentagon was "prepared for a full range of contingencies."